JPH07211569A - Manufacture of polymer complex rare-earth magnet - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of a polymer complex rare-earth magnet whose magnetic characteristic and mechanical strength are excellent. CONSTITUTION:In the manufacturing method of a polymer complex rare-earth magnet, a one-liquid epoxy resin is mixed with a rare-earth-based magnet powder, a coated magnet powder is prepared, the coated magnet powder is molded, and a molded product is formed. In the manufacturing method, 2-ethyl hexyl titanate and 3-cyanopropyl triethoxysilane in 0.1 to 0.5wt.% are mixed with the magnet powder, and two kinds of coated magnet powders are prepared. Then, the two kinds of coated magnet powders are mixed, a one-liquid epoxy resin is mixed with a mixed magnet powder, this mixture is molded by applying a molding pressure of 6 ton/cm<2> and an application magnetic field of 15kOe, a molded body is obtained, the molded body is hardened and treated at 150 deg.C for one hour, and the polymer complex rare-earth magnet whose magnetic characteristic and mechanical strength are excellent is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polymer composite type rare earth magnet having excellent magnetic properties and mechanical properties.

[0002]

2. Description of the Related Art It is well known in JISC2502 permanent magnet materials and the like that a magnetic powder and a binder are mixed and the polymer composite rare earth magnet is manufactured by extrusion molding, compression molding or injection molding. When a mixture of magnet powder and binder is produced by compression molding, a method of improving density and mechanical strength is proposed as a method of increasing magnetic properties and mechanical strength, such as adjusting powder particle size to increase molding pressure. Although these manufacturing methods are being improved, it is still not sufficient. As one of methods for improving such a problem, a method of coating magnetic powder with various coupling agents has been proposed. It is said that this method has the effect of changing the surface of the magnet powder from hydrophilic to lipophilic and improving the compatibility with the binder, and therefore it is possible to improve the filling rate, orientation and mechanical strength. However, even if these methods are adopted, the mechanical strength is lowered as the magnet characteristics are enhanced, and the magnetic characteristics are lowered if the mechanical strength is enhanced, and both the magnetic characteristics and the mechanical strength have not been enhanced. As a matter of course, with respect to the magnetic properties, the nonmagnetic binder and the additives are mixed, so that the magnetic properties are deteriorated by the volume. In particular, in recent years, it is expected to be applied to small motors, OA equipment, etc., and composite magnets are increasingly required to have thin-walled shapes, and it is important to improve mechanical strength without impairing magnetic characteristics. Has become.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a polymer composite type rare earth magnet having excellent magnetic properties and mechanical strength.

[0004]

The present invention relates to a method for producing a polymer composite magnet, which is produced by mixing a rare earth magnet powder with a resin and molding the mixture, in which 0.2-ethylhexyl titanate is added to the magnet powder. 1 to 0.5 wt% is mixed and coated to form a magnet powder, while 0.1 to 0.5 wt% of 3-cyanopropyl-triethoxysilane is added to the rare earth magnet powder.
A method for producing a polymer composite type rare earth magnet, which is characterized in that mixing and coating are performed to obtain a magnet powder, each of the coated magnet powder and the magnet powder is mixed, and the resin powder is molded using a resin. Also, the polymer composite type is characterized in that the mixing weight ratio of the magnet powder coated with 3-cyanopropyl-triethoxysilane and the magnet powder coated with 2-ethylhexyl titanate is 1: 3 to 1:13. It is a method for manufacturing a rare earth magnet.

[0005]

The magnetic material of the present invention is prepared by mixing 2-ethylhexyl titanate with 0.1 to 2-ethylhexyl titanate before mixing the binder and the magnetic powder.
By using a mixture of magnet powder coated with 0.5 wt% and magnet powder coated with 3-cyanopropyl-triethoxysilane 0.1-0.5 wt%, the filling amount of magnet powder due to both treatment effects. , The magnetic powder has a higher degree of orientation, magnetic properties and mechanical strength are improved, and both treatment effects are improved compared to the case where coating treatment is performed by simultaneously adding both coating treatment agents. The properties and mechanical strength are significantly improved. The surface treatment agent used in the present invention is represented by the following structural formula. 2-Ethylhexyl titanate is [C ₄ H ₉ CH (C
₂ H ₅₎ CH ₂ O] a ₄ Ti, 3- cyanopropyl - triethoxysilane _{NC (CH 2) 3 Si (} OC 2 H 5) 3
Is. The amount of the coating agent used is the most suitable for the purpose of the present invention. The mixing ratio of the 2-ethylhexyl titanate-coated magnet powder and the 3-cyanopropyl-triethoxysilane-coated magnet powder is the amount of the 2-ethylhexyl titanate-coated magnet powder. If it is too large or too small, the magnetic properties and mechanical strength are deteriorated, and the weight ratio is 1: 3 to 1:13, more preferably 1: 7 to 1: 9. The treatment method is generally known as a dry method, that is, a method of dissolving each coating treatment agent directly or in a small amount of solvent and dropping or spraying magnet powder while stirring, and a wet method, that is, a method of coating treatment with a large amount of solvent. After stirring and mixing with magnet powder by stirring,
Any method of removing the solvent by drying may be used. The magnet powder treated according to the present invention is then mixed with a resin and compression molded to obtain a composite magnet body. The magnet material composition obtained by such a method is not limited to compression molding and may be subjected to extrusion molding or injection molding.

[0006]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

[Example 1] 3-cyanopropyl-triethoxysilane was added to a powder of Sm ₂ Co ₁₇ type magnet alloy having an average particle size of 30 μm in an amount of 0, 0.1, 0.2.
After adding 0.3%, 0.4%, 0.5% and 0.6% by weight and thoroughly mixing, a treatment was carried out at 120 ° C. for 30 minutes. Then, one-part epoxy resin was added to the treated magnetic powder in an amount of 3.0 wt.
%, And thoroughly mixed, the resulting mixed magnet powder was molded with a compression molding machine at a molding pressure of 6 ton / cm ² and an applied magnetic field of 15
Molded under the condition of KOe (1194 KA / m) 9 × 1
A molded body of 0 × 10 mm was obtained. The molded body was cured at 150 ° C. for 1 hour. The evaluation results of the obtained magnet molded product are shown in FIG. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics were evaluated as an average value of 10 pieces.

[Example 2] ₂ -ethylhexyl titanate was added to powder of Sm ₂ Co ₁₇ system magnet alloy having an average particle size of 30 µm, and the amount of the magnet powder was 0, 0.1, 0.2, 0.3, 0.3.
After adding 4, 0.5 and 0.6 wt% and mixing well, 120 ℃
Was processed for 30 minutes. Then, 3.0 wt% of one-component epoxy resin was added to the magnet powder after the above treatment and thoroughly mixed, and the obtained mixed magnetic powder was molded with a compression molding machine at a molding pressure of 6 ton / cm ² and an applied magnetic field of 15 KOe ( 11
Molded under the condition of 94 KA / m) 9 × 10 × 10 mm
A molded body of was obtained. The molded body was cured at 150 ° C. for 1 hour. Fig. 1 shows the evaluation results of the obtained magnet molded products.
The results are shown in (b) and Table 2. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics were evaluated as an average value of 10 pieces.

From FIGS. 1 (a) and 1 (b), the amount of 3-cyanopropyl-triethoxysilane and 2-ethylhexyl titanate added to the magnet powder is preferably 0.1 to 0.5 wt%, and further preferably. 0.2-0.3
It was found to be wt%.

[Example 3] To a powder of Sm ₂ Co ₁₇ type magnet alloy having an average particle diameter of 30 μm, 0.2 wt% of 3-cyanopropyl-triethoxysilane was added to the magnet powder and thoroughly mixed, and then 120 ° C. Was processed for 30 minutes. Further, 0.2 wt% of 2-ethylhexyl titanate was added to the powder of the Sm ₂ Co ₁₇ system magnet alloy having an average particle size of 30 μm, and they were sufficiently mixed and then treated at 120 ° C. for 30 minutes. The magnet powders subjected to the respective coating treatments were thoroughly mixed in a weight ratio of 1: 1 to 1:15. Then, 3.0 wt% of one-component epoxy resin was added to each of the magnet powders subjected to this treatment and thoroughly mixed, and the resulting mixed magnet powders were molded at a compression pressure of 6 ton / cm ² by a compression molding machine. , Applied magnetic field 1
Molded under the condition of 5KOe (1194KA / m) 9 ×
A molded body of 10 × 10 mm was obtained. This molded body at 150 ° C
It was cured for 1 hour. The evaluation results of the obtained magnet molded products are shown in FIG. 2 and Tables 3 and 4. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics were evaluated as an average value of 10 pieces.

Comparative Example 1 In Comparative Example 1, a sample was obtained in the same manner as in Example 3 except that the surface treatment of 3-cyanopropyl-triethoxysilane and 2-ethylhexyl titanate was not performed in Example 3. It was This result is shown in Figure 2.
And Tables 3 and 4. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics were evaluated as an average value of 10 pieces.

[Comparative Example 2] 3-Cyanopropyl-triethoxysilane and 2-ethylhexyl titanate were simultaneously mixed so as to have the same addition ratio and total amount as in Example 3, and coating treatment was carried out. Otherwise, in Example 3 A sample was obtained in exactly the same manner as. The results are shown in FIG. 2 and Tables 3 and 4. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics were evaluated as an average value of 10 pieces.

[Example 4] R manufactured by General Motors
-TB rare earth permanent magnet powder MQ-1 average particle size 30μ
3-cyanopropyl-triethoxysilane was added to the powder of m in an amount of 0.3 wt% with respect to the magnet powder and mixed well, and then treated at 120 ° C for 30 minutes. In addition, 2 in the magnet powder
-Ethylhexyl titanate was added at 0.3 wt% and mixed well, and then treated at 120 ° C for 30 minutes. The coated magnet powders were thoroughly mixed in a weight ratio of 1: 1 to 1:15. Then, 3.0 wt% of one-component epoxy resin was added to the treated magnet powder and mixed well, and the obtained mixed magnet powder was molded at a molding pressure of 6 ton / c by a compression molding machine.
Molding was performed under the condition of m ² to obtain a molded body of 9 × 10 × 10 mm. The molded body was cured at 150 ° C. for 1 hour. The evaluation results of the obtained molded products are shown in FIG. 3 and Tables 5 and 6. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics were evaluated as an average value of 10 pieces.

Comparative Example 3 In Comparative Example 3, a sample was obtained in the same manner as in Example 4, except that the surface treatment of 3-cyanopropyl-triethoxysilane and 2-ethylhexyl titanate was not performed in Example 4. It was This result is shown in Figure 3.
And Tables 5 and 6. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics were evaluated as an average value of 10 pieces.

[Comparative Example 4] 3-Cyanopropyl-triethoxysilane and 2-ethylhexyl titanate were simultaneously mixed so that the same addition ratio and total amount as in Example 4 were obtained, and coating treatment was carried out. A sample was obtained in the same manner as in. The results are shown in FIG. 3 and Tables 5 and 6. The number of molded articles of the obtained magnet is 10 as a sample. Various characteristics are 1
It was evaluated as an average value of 0 pieces.

As shown in FIGS. 2 and 3, magnetic properties and mechanical strength are improved as compared with untreated and simultaneous addition of both. Further, regarding the mixing ratio of the treated powder, it is found that 3-cyanopropyl-triethoxysilane and 2-ethylhexyl titanate are preferably 1: 3 to 1:13, more preferably 1: 7 to 1: 9.

The rare earth permanent magnet powder described above is sintered R
Examples of the powder of the -TB magnet include Nd ₂ Fe ₁₄ B powder and the like, but the powder is not limited thereto.
As for the Sm-Co rare earth magnet, SmCo ₅ type rare earth magnet powder, Ce (CoFeCuM) ₅ magnet S
mR (CoFeCuM) _z magnet (R = Pr, Ne, C
Examples thereof include powders such as e), but are not limited thereto.

[0018]

As described above, the effect of improving the magnetic properties and the mechanical strength can be obtained by the coating method of the present invention. In the future, the demand for polymer composite magnets mainly in OA equipment will be further expanded, and at the same time, the trend will be toward miniaturization, thinning and weight reduction, so that the industrial value of the present invention will be extremely large.

[Brief description of drawings]

FIG. 1 shows the relationship between the amount of 3-cyanopropyl-triethoxysilane and 2-ethylhexyl titanate added to a magnet powder and the mechanical strength and magnetic properties of a molded body according to Examples 1 and 2 of the present invention. Fig. FIG. 1A is a diagram showing the relationship between the amount of 3-cyanopropyl-triethoxysilane added to the magnet powder according to Example 1 of the present invention and the mechanical strength and magnetic properties of the molded product. FIG. 1 (b) is a diagram showing the relationship between the amount of 2-ethylhexyl titanate added to the magnet powder and the mechanical strength and magnetic properties of the molded product according to Example 2 of the present invention.

FIG. 2 is a diagram showing the relationship between the mixing ratio of 3-cyanopropyl-triethoxysilane: 2-ethylhexyl titanate of the magnet powder according to Example 3 of the present invention and the mechanical strength and magnetic properties of the molded product. FIG. 2 (a) shows the mixing ratio of the coated magnet powder according to Example 3 of the present invention and the mechanical strength of the molded product (the bending strength).
FIG. FIG. 2B is a diagram showing the relationship between the mixing ratio of the coated magnet powder according to Example 3 of the present invention and the magnetic characteristics of the molded product.

FIG. 3 is a diagram showing the relationship between the mixing ratio of 3-cyanopropyl-triethoxysilane: 2-ethylhexyl titanate in the magnet powder according to Example 4 of the present invention and the mechanical strength and magnetic properties of the molded product. FIG. 3 (a) shows the mixing ratio of the coated magnet powder according to Example 4 of the present invention and the mechanical strength (flexural strength) of the molded product.
FIG. FIG. 3B is a diagram showing the relationship between the mixing ratio of the coated magnet powder and the magnetic characteristics of the molded product according to Example 4 of the present invention.

[Table 3]

[Table 4]

[Table 5]

[Table 6]

Claims (2)

[Claims] 1. A method for producing a polymer composite-type magnet, which is obtained by mixing a rare earth magnet powder with a resin and molding the mixture, wherein 2-ethylhexyl titanate is added to the magnet powder in an amount of 0.1 to 0.1%.
0.5 wt% is mixed and coated to make a magnet powder, while 0.1-0.5 wt% of 3-cyanopropyl-triethoxysilane is mixed to a rare earth magnet powder and coated to be a magnet powder. A method for producing a polymer composite type rare earth magnet, which comprises mixing a coated magnet powder with a magnet powder and molding the resin powder with a resin. 2. A mixing weight ratio of the magnet powder coated with 3-cyanopropyl-triethoxysilane and the magnet powder coated with 2-ethylhexyl titanate is 1: 3.
The ratio is 1:13 to 1:13. The method for producing a polymer composite rare earth magnet according to claim 1, wherein